Emapalumab

證據等級: L5

預測適應症: 10 個

Emapalumab: From Primary Hemophagocytic Lymphohistiocytosis to Infection-Associated Hemophagocytic Lymphohistiocytosis

Note on indication selection: This evidence pack contains 10 TxGNN-predicted indications for emapalumab, ranked by model score. The #1-ranked node (autosomal recessive familial Mediterranean fever) has zero supporting trials or literature (Evidence Level L5, Hold). This report instead focuses on “hemophagocytic syndrome associated with an infection” (rank 3, score 99.99%), the only candidate in this pack backed by an actual clinical trial and a substantial literature base, and the highest decision stage reached (S2, Proceed with Guardrails). The other HLH-spectrum candidates (malignancy-associated HLH, XLP1/SH2D1A deficiency) are mechanistically related but lack direct evidence and are noted only in passing.

One-Sentence Summary

Emapalumab is an anti-interferon-gamma (IFN-γ) monoclonal antibody originally established for Primary Hemophagocytic Lymphohistiocytosis (pHLH). Within this evidence pack, TxGNN predicts it may also be effective for infection-associated (secondary) hemophagocytic lymphohistiocytosis — most notably EBV-triggered HLH — with 1 clinical trial and 20 publications currently identified, though the trial was terminated with only 7 patients enrolled.

Quick Overview

Item	Content
Original Indication	Primary Hemophagocytic Lymphohistiocytosis (pHLH) — inferred from literature in this pack (e.g., PMID 32374962); not recorded in the regulatory dataset (see US Market Status)
Predicted New Indication	Hemophagocytic syndrome associated with an infection (secondary/infection-associated HLH)
TxGNN Prediction Score	99.99%
Evidence Level	L3
US Market Status	Not marketed (per this dataset — see note below)
Number of NDAs	0
Recommended Decision	Proceed with Guardrails

Note on market status: The regulatory dataset in this evidence pack records 0 licenses and “not marketed.” A Blocking data gap (DG001) flags that the official label (warnings/contraindications) could not be retrieved, so this status should be treated as a data-collection gap rather than a confirmed absence of approval, and should be re-verified from primary regulatory sources before use in decision-making.

Why is This Prediction Reasonable?

Detailed formal mechanism-of-action data is not available in the structured original_moa field (marked as a data gap, DG002). However, the literature captured in this evidence pack is consistent: emapalumab is described repeatedly as “a fully human monoclonal antibody that neutralizes interferon-gamma (IFN-γ)… a key cytokine driving the inflammation and tissue damage seen in HLH” (NCT03985423 summary; PMID 32374962, 39117840, 38014905).

Primary HLH and infection-associated (secondary) HLH share the same core pathophysiology: uncontrolled IFN-γ-driven macrophage activation and cytokine storm. The literature in this pack explicitly frames secondary HLH — including infection-, malignancy-, and rheumatologic-disease-associated forms — as sharing the hyperinflammatory pathobiology of primary HLH, with EBV infection being the dominant infectious trigger described across multiple case series (PMID 38691058, 39719162, 39331881, 41066671). This makes the extension of an IFN-γ-neutralizing mechanism from primary to infection-triggered HLH a direct, biologically grounded extrapolation rather than a speculative new mechanism — TxGNN’s high score for this node reflects a real mechanistic neighbor to the drug’s established indication, not an artifact.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT03985423	Phase 2/3	Terminated	7	Open-label, single-arm study of emapalumab in adult HLH patients (etiologies include autoimmune disease, infection, malignancy) evaluating efficacy, safety and pharmacokinetics; terminated early with only 7 of planned enrollment completed, limiting statistical power.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
32374962	2020	Cohort (pivotal)	N Engl J Med	Foundational efficacy/safety study of emapalumab in primary HLH in children; establishes the IFN-γ-neutralization mechanism this prediction extrapolates from.
41337692	2026	Cohort (real-world US)	Blood Advances	REAL-HLH study: retrospective chart review across 33 US hospitals on real-world emapalumab use and outcomes in secondary HLH populations, including malignancy- and infection-triggered cases.
38014905	2024	PK/Exposure-safety analysis	Pediatric Blood & Cancer	Exposure-safety relationship analysis for emapalumab in HLH; examines risk of immune dysfunction/immunosuppression from IFN-γ blockade.
34096649	2021	Review	Acta Paediatrica	Reviews virus-triggered secondary HLH, distinguishing it from primary HLH and describing shared hyperinflammatory/hypercytokinemic mechanisms.
39117832	2024	Review	Adv Exp Med Biol	Discusses overlap between primary HLH, secondary HLH (including infection-associated), and sepsis-induced MODS, and implications for targeted therapy.
39117840	2024	Review	Adv Exp Med Biol	Reviews the role of IFN-γ in cytokine storm syndromes and summarizes anti-IFN-γ therapeutic approaches, including emapalumab.
38691058	2024	Case series	J Pediatr Hematol Oncol	Emapalumab combined with ruxolitinib and dexamethasone effectively treated EBV-associated HLH complicated by multiorgan damage and severe infection.
39719162	2025	Case series	Transplant Immunology	Low-dose emapalumab combined with chemotherapy controlled EBV-associated HLH in 3 adult patients.
39331881	2024	Case series	Medicine	Case series describing emapalumab as an effective therapeutic option for EBV-associated HLH refractory to standard protocols.
41066671	2025	Case series	Annals of Medicine	Emapalumab improved outcomes in 3 pediatric EBV-HLH patients with multiple organ dysfunction syndrome.

US Market Information

According to this evidence pack’s regulatory dataset, no NDA/BLA licenses are on file for emapalumab and market status is recorded as “not marketed.” This coincides with Blocking data gap DG001 (TFDA/label warnings and contraindications not retrieved), so the official approval and label status should be independently re-verified rather than relied on from this dataset alone.

Safety Considerations

Please refer to the package insert for safety information. No structured warnings, contraindications, or drug-interaction data were retrieved in this evidence pack (DDI query status: not found).

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: The mechanistic case is strong — infection-associated (especially EBV-triggered) secondary HLH shares the same IFN-γ-driven pathophysiology as emapalumab’s established primary-HLH mechanism, and this is the only predicted indication in the pack with any clinical trial or literature support (1 terminated Phase 2/3 trial, 10+ relevant publications, evidence level L3). However, the supporting trial was terminated with only 7 patients and no data reach RCT-level confirmation specifically for infection-triggered HLH; most direct clinical support is case-series level.

To proceed, the following is needed:

Resolve Blocking data gap DG001: obtain official label warnings/contraindications from the regulatory source
Resolve High-severity data gap DG002: confirm formal MOA documentation via DrugBank
Investigate why NCT03985423 was terminated and whether follow-on/replacement trials exist
Seek RCT-level or larger prospective data specifically in infection-/EBV-associated secondary HLH (current evidence is cohort/case-series level)
Obtain formal drug-drug interaction data (current query: not found)
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.